I realize that an insertion inside a bookmark will expand the bookmark to match, and deleting something inside a bookmark will make it smaller. That is exactly what I expect. But I am seeing both ends of a bookmark moving down, for no apparent reason, by several lines toward the end of the document. I don't see what I could do inside the bookmark to cause this. I also find it strange that apparently no one else has reported this problem. I am using Word 365-2016 in compatibility mode on Win 7. I have not been able to isolate what actions I am doing that cause this: changing styles (which are pretty disorganized), adding text elsewhere, saving and opening the document, etc.